205212120164 has 12 divisors (see below), whose sum is σ = 359507784300. Its totient is φ = 102495610368.

The previous prime is 205212120163. The next prime is 205212120193. The reversal of 205212120164 is 461021212502.

It can be written as a sum of positive squares in 2 ways, for example, as 19113062500 + 186099057664 = 138250^2 + 431392^2 .

It is a super-2 number, since 2×205212120164² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (205212120163) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27608249 + ... + 27615680.

It is an arithmetic number, because the mean of its divisors is an integer number (29958982025).

Almost surely, 2^205212120164 is an apocalyptic number.

It is an amenable number.

205212120164 is a deficient number, since it is larger than the sum of its proper divisors (154295664136).

205212120164 is a wasteful number, since it uses less digits than its factorization.

205212120164 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55224862 (or 55224860 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 26.

Adding to 205212120164 its reverse (461021212502), we get a palindrome (666233332666).

The spelling of 205212120164 in words is "two hundred five billion, two hundred twelve million, one hundred twenty thousand, one hundred sixty-four".